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Low-energy Cathodoluminescence for (Oxy)Nitride Phosphors
Published on: November 15, 2016
Multi-phonon assisted upconversion emission and power dependence studies in LaF3:Er3+ phosphor
A K Singh1, K Kumar, A C Pandey
1Department of Ceramic Engineering, IIT-BHU, Varanasi 221 005, India.
Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
|February 13, 2013
Summary
Lanthanum fluoride doped with erbium (LaF3:Er3+) phosphors exhibit tunable upconversion emissions. Specific emission bands at 411 nm and 488 nm function as optical switches, responding to changes in excitation power and temperature.
Area of Science:
- Materials Science
- Solid State Physics
- Luminescence
Background:
- Lanthanum fluoride (LaF3) doped with trivalent erbium (Er3+) ions are promising upconversion (UC) materials.
- Understanding the UC mechanisms and optical properties is crucial for developing advanced photonic devices.
Purpose of the Study:
- To synthesize LaF3:Er3+ phosphor using chemical precipitation.
- To investigate the upconversion emission properties under 532-nm excitation.
- To explore the temperature-dependent UC behavior and its correlation with power-dependent studies.
Main Methods:
- Chemical precipitation synthesis of LaF3:Er3+ phosphor.
- Spectroscopic analysis of upconversion emission under 532-nm laser excitation.
- Temperature-dependent luminescence measurements.
Main Results:
- Observed two-photon absorption UV bands at 325, 342, 383, 403, and 411 nm.
- Identified multi-phonon assisted energy migration leading to new emission channels at 440, 453, and 488 nm.
- Demonstrated that UC bands at 411 and 488 nm act as optical switches due to intensity reversal with increasing excitation power or temperature.
- Observed Planck blackbody-like continuum emission at higher excitation powers.
Conclusions:
- The synthesized LaF3:Er3+ phosphor exhibits complex upconversion emission characteristics.
- The identified optical switching behavior of specific UC bands offers potential for novel optoelectronic applications.
- The study provides insights into energy transfer mechanisms and temperature-dependent luminescence in LaF3:Er3+ systems.
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